Heater box cable refurbishment

[Driv3r]

Often overlooked on any restoration of a heater box. This article details a great upgrade. 

So I know that the heater valve/fresh air Bowden cable is still available but I couldn't find the two flap cables. So initially I restored my heater box with old cables because they were working. But the thought of those cables getting rusted and stuck again, was daunting.
 
I've decided to do a research on alternative options. The oem metal wire has 1.4mm diameter and it's not so strong. The wire cover itself is made of metal spring and vinyl skin but over time, rusty metal cause friction and eventually wire or lever get stuck.
 
I decided to search for a stainless steel wire in bigger diameter that would strengthen the lever force and basically won't rust. So I went to local hardware store and bought stainless steel wire in 1.6mm diameter.
 
To replace the old wire cover, I chose Shmano brake line sleeve. It's made for mountain bike application with extreme brake use conditions and is much more resistant and durable than the oem cable. It's available in most colors (of course I went with inka!) for around $6 meter. The brake sleeve has 5mm external and 2mm internal diameters. Be aware of fake copies out there!
 

 
After using the stainless steel wire with Shimano sleeve, I notice a complete improvement with almost no friction. Here is a comparison:
 

 
The hardest part of copying the oem wire was the swirled attachment tip to the lever shaft. Stainless steel wire was really hard to bend and it came coiled under tension which made it harder to bend in opposite direction but I finally figured it out. Using a screwdriver with same diameter as the lever shaft, hold the wire with a plier over the screwdriver and use your thumb to bend it around the screwdriver.
 

 
Then cut the excess with wire cutter. Once you master these, the rest is self explanatory.
 

 

 

 

 
The lever movement has improved to better than the oem part and will last longer. I can move levers with my finger nails. I hope this help so many of members out there looking for better, more reliable and cheaper alternative.
 
Cheers.
 
 

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[zambo]

Excellent write up and pics. Great job!

[jgerock]

Bravo!

[halboyles]

Excellent indeed!  Well Done!

[halboyles]

BTW, if your local hardware shop doesn't speak the metric, 1.6mm is 14 gauge

[yeewiz]

Very nice write up!  Thanks for a great upgrade article!

[Vicleonardo1]

Love the write up!

Two questions:

1.Do  you think buying a shimano brake cable and housing set would do the job?  Some Shimano kits have a  1.6mm wire with 5mm housing. 

2. What total length of wire (and tubing) did you need? 

 

Very cool and innovative idea.

 

Cheers! 

[Driv3r]

Love the write up!

Two questions:

1.Do  you think buying a shimano brake cable and housing set would do the job?  Some Shimano kits have a  1.6mm wire with 5mm housing. 

2. What total length of wire (and tubing) did you need? 

 

Very cool and innovative idea.

 

Cheers! 

 

Good question and let me clear this for others as well:

 

There are two different types of stainless steel wire sold online or in hardware stores. You would want to buy the solid type not the rope (bunch of wires stacked together) type.

 

The problem with rope type wire is that due to its high flexibility, it cannot transfer force without being covered by wire sleeve (like where it's used to manage bicycle gear shifter but it could be installed in bicycle brake system without wire sleeve due to brake system needing constant pull force rather than push force (heater box).

 

We cannot use wire sleeve inside the heater box in front of the core due to constant heat although the valve/fresh air cables are installed inside of the box but behind the core and kept cool by the fan.

 

And to answer your second question, I went through 8m of wire but the actual use is less than 2m. I recommend buying 10m and make a few to get better at it.

 

The grade of stainless steel wire I used is 316 which is marine grade and it basically won't rust but you can also use 304 with same results.

 

Please try to copy the direction of oem wire where it connects to individual rods.

 

 

[Driv3r]

If you can't find stainless steel wire to specifications then try 1.4mm or 1.5mm, they would still work better than oem iron wire.

The wire I used was 316 grade but you can use 304. Some sellers on eBay sell the softer type, make sure it's the hard stainless steel.

16mm is 0.063" and equal to 14 gauge. If you still can't find this wire then lookup stainless steel MIG welding wire in 1.4mm,1.5mm or 1.6mm or call a welding shop and ask if you can buy some from them. They use a 15kg rolls and most shops are happy to cut some for you.

[bobthomas]

I don't anticipate needing the info you've provided.  Still, it is a great write up with excellent pictures. 

We should all do this sort of thing more.  Thanks.

[halboyles]

On 5/10/2017 at 5:11 PM, Driv3r said:

Please try to copy the direction of oem wire where it connects to individual rods

This is very important as the cable ends are "handed".  As I mentioned in a previous post, you can use either the fresh air or defrost OEM cable for both purposes by just twisting one end 180°.   

[pehlivanov_tii]

Great idea. I have just completely refurbished my heater box and i spent a lot of time with adjusting and assembling the cable which controls the heater valve. And i had assembled and disassembled the heater box 2-3 times already and i WILL NOT do that again, but if i knew that before i would do this for sure. 

The cable which needs replacement more than any other cable is the one that controls the heater valve. When i refurbished my heater box i used 3 heater boxes to make one good. From the 3 heater boxes, 2 of that cables were broken in the place where they go through the hole of that strange NLA bolt. I was lucky that the 3rd cable was still strong and the funny fact is that this cable came from the most dead and rusty 2002 (68) that you can imagine lol. I hope it will last few more years.

[Driv3r]

Great idea. I have just completely refurbished my heater box and i spent a lot of time with adjusting and assembling the cable which controls the heater valve. And i had assembled and disassembled the heater box 2-3 times already and i WILL NOT do that again, but if i knew that before i would do this for sure. 
The cable which needs replacement more than any other cable is the one that controls the heater valve. When i refurbished my heater box i used 3 heater boxes to make one good. From the 3 heater boxes, 2 of that cables were broken in the place where they go through the hole of that strange NLA bolt. I was lucky that the 3rd cable was still strong and the funny fact is that this cable came from the most dead and rusty 2002 (68) that you can imagine lol. I hope it will last few more years. [emoji4]

Problem with reusing the oem cable cover is that it basically get rusted soon and blocks the movement of valve cable causing breakage. Sure you can redo the heater box in a few years but you need to pull the dash off, possibly drain the radiator and go through the whole refurbishment again. Better do a proper job and set it for another 40 years (hopefully). [emoji1]

[pehlivanov_tii]

47 minutes ago, Driv3r said:

 

...... but you need to pull the dash off, possibly drain the radiator and go through the whole refurbishment again. Better do a proper job and set it for another 40 years (hopefully).

 

I will go to the bike shop tomorrow...

[Stevenc22]

Great job. Always thought about trying that but never did!